Melanomas of the uveal tract comprise nearly all primary intraocular malignancies in adults, yet risk factors for the disease remain obscure. We propose a three-year case-control study in whites with approximately 400 cases and 800 controls to attempt to determine the risk factors for ocular melanoma. All adults between the age of 20 and 74 years diagnosed as having ocular melanoma at the UCSF ocular oncology unit between January 1, 1980 to July 1, 1986 and who reside in the western United States will comprise the case group. This sample size represents an unusually large accumulation of cases of this rare tumor (most common eye tumor). Healthy controls will be chosen using random digit dialing. Specific aims are: 1) to identify risk factors for ocular melanoma in whites; 2) to determine whether any identified risk factors vary by age or sex of the patient; 3) to indicate industries or occupations where risk of ocular melanoma is higher than in the control group (for use in future studies conducted in specific occupations). Cases and controls will be interviewed by telephone regarding characteristics such as their occupational, residence and medical histories with special reference to oral contraceptive use and parity status in women, exposure to chemicals, fluorescent light and to sunlight, eye and hair color, education and income, marital status, religious preference, height, weight, smoking history, leisure time activities (indoors or outdoors), previous ocular conditions, presence of nevi, etc. We will examine the relationship between ocular melanoma and exposure characteristics using the multiple logistic model and methods developed by Mantel and Haenszel.